An Iranian military official accused Siemens of cooperating with the U.S. and Israel in a cyberattack on the country's nuclear infrastructure, Haaretz reports.

"Our executive officials should legally follow up the case of Siemens SCADA software which prepared the ground for the Stuxnet virus," said Gholamreza Jalali, Iran's civilian defense chief. "The Siemens company must be held accountable and explain how and why it provided the enemies with the information about the codes of SCADA software and paved the way for a cyber attack against us."

Jalali offered no evidence that Siemens had been involved in the attack. After Stuxnet was revealed and detected last year, the German company released software that detects Stuxnet on infected systems and removes it.

The Iranian accusation is the latest in a string of public statements about the worm. The Iranian government has vacillated between downplaying the importance of Stuxnet and lashing out at its purported creators -- the U.S. and Israel. It's thought that Stuxnet targeted uranium centrifuges that produce the key isotopes for atomic weapons. What we don't know is how well Stuxnet worked. Did it slow down the nuclear program or is the Iranian anger about it a big head fake? As our own Jeff Goldberg put it, "I don't know. Even the people who know don't know."